Abstract
The rolling contact fatigue damage called pitting or spalling develops more frequently in surfaces with negative than positive slip. Since normal line loads do not cause any tensile surface stresses this investigation considers the effects of small point shaped asperities. Shear traction causes tensile stresses at the trailing edge of asperities entering the contact at negative slip. At positive slip the tensile stresses appear at the leading edge when the asperities exit the contact. It was found that the trailing edge of the asperity breaks through the lubrication film at contact entry. This causes negative slip to be more detrimental than positive slip. At negative slip the location of large frictional shear stresses and tension stresses from normal asperity contact coincide.
Highlights
Loaded gear and bearing surfaces will eventually fail due to rolling contact fatigue (RCF)
It is established [1] that the damage almost exclusively develops where friction acts against the rolling direction
Asperity effects were captured by solving the differential equation in both the rolling direction (RD) and the transverse direction (TD)
Summary
Loaded gear and bearing surfaces will eventually fail due to rolling contact fatigue (RCF). It is established [1] that the damage almost exclusively develops where friction acts against the rolling direction (negative slip). The process starts with fatigue initiation at the tip of the sea-shell shaped pit. It slowly grows in the forward rolling direction [1]. On the outside of the contact entering or exiting asperity the tensile stress may be high enough to cause crack initiation and growth, see Fig. 1b. Simulations, based on rolling contacts with asperities and a mode I crack direction criterion, shows that the full profile agrees with the sea-shell pit shape [3]. The goal was to show that the asperity point load mechanism can explains why pits initiates more often for negative than positive slip
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
